The switch mechanism of the present invention may be used and is intended for actuation by a powered carriage movable along an elongated guide channel. One example of this is a closure operator or garage door operator wherein a motor-powered carriage is movable along a horizontal guide channel and is connected to open and close an overhead-type or upward opening door. Such switch mechanisms may be used as limit switches to turn off the electric motor in the garage door operator at the up limit and closed limit of the door.
One example of such a limit switch is shown in U.S. Pat. No. 3,439,134, issued Mar. 28, 1966. This switch was suitable for use in a garage door operator, but incorporated a total of 13 parts, which was expensive in production of the individual parts and also expensive in the assembly of such parts in order to obtain proper operation thereof.
Such limit switches have been known and used for many purposes in the art and, as an example, may be used in an automatic garage door wherein it is desired to electrically deactuate an electric motor when the door has arrived at either an open or closed position. Because of the inertia of the door and mechanism which engages and actuates the switch, it is often necessary to make provision for overtravel without damage to the switch, i.e., the contacts or any other actuated part of the switch. Many devices of this type have been relatively complicated in construction and operation and, as a result, have been relatively expensive to manufacture.